1. Field of Invention
The present invention relates to a combination lock, and more particularly to a combination lock having no keyholes and lock member hidden inside the lock body of the combination lock.
2. Description of Related Arts
A combination lock is a type of padlock, wherein a sequence of numbers or symbols is used to open or unlock the lock. However, the lock code of the combination lock is a combination of the numbers or symbols but not the array of numbers or symbols. Accordingly, there are two types of combination lock, i.e. electronic combination lock and mechanical combination lock. The electronic combination lock generally comprises an electro-magnetic lock assembly or an electronically controlled latch, wherein when an input code entered by a user matches with a preset code, the electro-magnetic lock assembly is automatically actuated in an unlocked position in order to unlock the electronic combination lock. However, the major drawback of the electronic combination lock is that the electronic combination lock must be electrically connected to a power source. In other words, the electronic combination lock will not be operated without any power source. In addition, since the electro-magnetic lock assembly must incorporate with an internal electronic chip and other electronic components, the breaking resistance or tensile strength of the electronic combination is weaker than that of the mechanical combination lock.
The mechanical combination lock generally comprises a plurality of rotating dials individually rotating about an axle to link with a lock bolt, wherein when each of the rotating dials is rotated at a predetermined position, the lock bolt is free to move in order to unlock the mechanical combination lock. Since the user must manually rotate a plurality of outer driving rings one-by-one to rotate the corresponding rotating dials respectively, the operation of the mechanical combination lock is complicated. Therefore, the mechanical combination lock cannot be incorporated with any automatic actuation unit to automatically complete the unlocking operation of the mechanical combination lock.